1. Field of the Invention
The present invention relates generally to battery packs and, more particularly, to intelligent battery pack labels for use with battery packs.
2. Related Art
Sudden cardiac arrest, i.e., a heart attack, has been attributed to over 350,000 deaths each year in the United States, making it one of the country's leading medical emergencies. World-wide, sudden cardiac arrest has been attributed to a much larger number of deaths each year. One of the most common and life threatening consequences of a heart attack is the development a cardiac arrhythmia commonly referred to as ventricular fibrillation. When in ventricular fibrillation the heart muscle is unable to pump a sufficient volume of blood to the body and, more importantly, to the brain. Ventricular fibrillation is generally identifiable by the victim's immediate loss of pulse, loss of consciousness and a cessation of breathing. The lack of blood and oxygen to the brain may result in brain damage, paralysis or death to the victim.
The probability of surviving a heart attack or other serious heart arrhythmia depends on the speed with which effective medical treatment is provided. There are four critical components of effective medical treatment that must be administered to a victim of sudden cardiac arrest: (1) early cardiopulmonary resuscitation to keep the blood oxygenated and flowing to the victim's brain and other vital organs; (2) early access to emergency care; (3) early cardiac defibrillation to restore the heart's regular rhythm; and (4) early access to advanced medical care. If prompt cardiopulmonary resuscitation is followed by defibrillation within approximately four minutes of the onset of symptoms, the victim's chances of surviving sudden cardiac arrest can approach or exceed forty percent. Prompt administration of defibrillation within the first critical minutes is considered one of the most important components of emergency medical treatment for preventing death from sudden cardiac arrest.
Cardiac defibrillation is an electric shock that is used to arrest the chaotic cardiac contractions that occur during ventricular fibrillation and to restore a normal cardiac rhythm. To administer this electrical shock to the heart, defibrillator pads are placed on the victim's chest, and an electrical impulse of the proper size and shape is administered to the victim in the form of an electric shock. While defibrillators have been known for years, they have typically been large and expensive making them unsuitable for use outside of a hospital or medical facility.
More recently however, portable external defibrillators for use by first responders have been developed. A portable defibrillator allows proper medical care to be given to a victim earlier than preceding defibrillators, increasing the likelihood of survival. Such portable defibrillators may be brought to or stored in an accessible location at a business, home, aircraft or the like, ready for use by first responders. With recent advances in technology, even a minimally trained individual can operate conventional portable defibrillators to aid a heart attack victim in the critical first few minutes subsequent to onset of sudden cardiac arrest.
Portable defibrillators require an energy source other than an alternating current source to operate in the anticipated environment. Although many manufacturers have provided customized battery packs for their portable defibrillators, some are designed to use a standard, commonly available, rechargeable battery pack, such as those used in video camcorders. These defibrillators incorporate standard mechanical and electrical adapters to mechanically and electrically connect the standard battery packs to the defibrillator. The use of standard battery packs allows for a simple and less expensive battery. Such battery packs may be, for example, a sealed lead acid (SLA) battery, a nickel cadmium (NiCd) battery, a lithium battery or the like.
Those manufacturers that have chosen to use the standard, commonly available rechargeable battery packs have designed their portable defibrillators to receive such a battery pack in a battery pocket. That is, the battery pocket is designed to physically accommodate, mechanically connect and electrically interface to the desired standard battery pack. The battery packs are manufactured with a certain tolerance in their minimum and maximum physical dimensions, the placement and dimensions of recesses and electrical contacts, and other electrical or mechanical features. Since these dimensions vary somewhat among battery pack manufacturers and are not held to strict tolerances by an individual manufacturer, the battery pockets are generally configured with dimensions sufficient to receive slight variations of the desired standard battery pack.
More recently, additional functionality has been incorporated into battery packs to create what is commonly referred to as smart or intelligent battery packs. The primary purpose of intelligent battery packs has been to provide power management circuitry in addition to one or more battery cells, all of which is integrated within the battery pack case. Such power management functions may include, for example, determining the present charge state of the battery pack, generating status information and the like. The advent of intelligent battery packs has resulted in the functional division of battery packs and has given rise to the vernacular "smart" and "non-smart" battery packs to denote those that do and do not, respectively, include power management or other processing capabilities.
However, because conventional intelligent battery packs usually have an external shell containing the smart circuitry, they have dimensions greater than standard, non-smart battery packs. As a result, smart battery packs often will not fit within the battery pocket of a portable defibrillator designed to operate with an equivalent standard battery pack. This has left manufacturers of conventional defibrillators with few options when incorporating power management functions into the device. One approach has been to redesign the battery pocket to accommodate the smart battery pack. However, redesigning defibrillator to encompass the larger intelligent battery pack is extremely costly and renders the defibrillator incapable of operating with the standard, non-smart battery packs. As a result, such modified defibrillators become more costly to operate since such smart battery packs are not readily available and are generally more expensive.
Alternatively, manufacturers may implement the desired power management functionality in the defibrillator itself. This approach has drawbacks as well. Implementing power management functions in the portable defibrillator often requires other portions of the defibrillator to be redesigned to accommodate the associated hardware, and often increases circuit density. In addition to the cost of such redesign efforts, this may also produce potentially undesirable results, such as increasing electrical noise or overheating. Also, some functions such as a fuel gauge of a smart battery cannot be implemented except by circuitry that remains permanently attached to the battery.
What is needed, therefore, is a smart battery pack that can operate in a battery pocket designed to accommodate a standard, non-smart battery pack.